I think that what we need in order to understand and resolve these
issues is a really good mechanical cochlear model.
Suggestions, anyone?
Bob
Leon Van Noorden wrote:

Now I start to think about it is clear that timbre perception is our
capacity to recognize how a sound is generated and through which
filters it comes to our ear. In the good old days of the Institute for
Perception Research in Eindhoven we had a demonstrator of the
"klinker driehoek" (vowel triangle). This triangle lays in the x-y
plane of which the two dimensions are the first two formants of
vowels. In this triangle you can of course draw a wheel. The
demonstrator was implemented on 80 by 80 cm x - y plotter that you
could move by hand with a knob at the crossing of the two arms. With
some exercise you could speak with it and make sentences like " I owe
you ".
To day you could easily implement it wit a touch screen and software
like max/msp or ableton live. I think this is a fully parametrized
space. Bye from Bogota.

Hello list,
We are all familiar with the notion of a visual color wheel, e.g., a
continuous, circular representation of colors in some color space such
as HSV. (Here's a wikipedia page with some visual examples:
http://en.wikipedia.org/wiki/Color_wheel)
Of course, there are many different color wheels, given that there are
many different color spaces in which to model them.
I'm looking for the auditory equivalent of a color wheel. Namely, a
parametrized, continuous method for generating a series of sounds that
form a "perceptual loop" that has no perceived gaps.
I've coded a several of these, e.g., a violin morphing into a piano
morphing into a clarinet, which then morphs back into a violin. They
are all playing middle C and the ASDR envelopes for the generated,
equal-length samples are identical.
I'm doing this to measure discriminative acuity in distinguishing sounds
along the auditory wheel, as part of a larger multimodal perceptual
experiment.
However, what I've found is that people with musical backgrounds have
far greater discriminatory power in separating nearby sounds than those
who have little training. There are also "unintended" clues, such as
harmonic complexity, which people appear differentially sensitive to.
Thus, I wonder if there is any work in creating such an auditory wheel
that might be expected to reduce bias due to background and/or culture.
E.g., using a heptatonic music scale may not be a good idea and sounds
derived from familiar instruments are probably best avoided as well. I
would like participants to be on an equal auditory footing, so to speak.
I'll repeat that it is essential that there be a "loop" in the sound
presentation that is not due to a simple repetition of sounds, e.g., a
sine wave rising and then falling in frequency would not be useful.
Any pointers, suggestions, code, etc., would be most welcome.
Best,
Michael Coen